Boring-tool.



No. 882,530; PATENTED MAR. 1'7, 1908. R. N. MELVIN.

BORING TOOL.

APPLICATION FILED MAY 6, 1007.

vvvvvv UNITED STATES PATENT OFFICE.

ROY N. MELVIN, OF MEADVILLE, PENNb YLVANIA, ASSIGNOR OF ONEHALF TO WINTERS D. HAMAKER, OF MEADVILLE, PENNSYLVANIA.

BORING-TOOL.

Specification of Letters Patent.

nassasso.

Patented March 17, 1908.

Application 'filed May 6, 1907. Serial No. 372,215.

acter yet of great strength, for clamping the cutters in position.

To these ends my invention is embodied,

in preferable form, in the device hereinafter described and illustrated in the accompanying drawings.

In these drawings, Figure 1 is a View partly in elevation and partly in vertical section of my improved boring tool; Fig. 2 is a bottom plan view of the clamping ring; Fig. 3 is a top plan view with clamping ring removed; Fig. 4 is a bottom plan view of adjusting ring; Figs. 5 and 6, details of adjusting tool and Figs. 7 and 8, details of cutter.

Referring to the drawings, 1 is the shank of the tool and 2 is a fixed collar mounted on the shank. The'stem of the tool is threaded at 3, beyond this collar, and such threaded portion is engaged by a lock-nut 4. The outer portion 4 of the stem has a smooth surface and on this part is mounted a vertically movable sleeve 5, constituting the head of the tool and the support for the cutters. A vertical key.6 is mounted in adjacent slots in the head and stem and serves to prevent rotary movement of the head, while permitting longitudinal movement thereof.

Extendin inwardl from the plane outer surface of t e shoul er 7 of the head, is a V-shaped socket 8, having one of its walls 9, at a greater angle to the plane surface of the Shou der than the other wall 10 whereby a shearing angle will be given to the projecting forward longitudinal edge of the cutter.

Adapted to be supported substantially bodily by this socket, is a cutter 11 equilaterally triangular in cross-section, and havmg similar longitudinal and end faces. The

end of the. cutter is round square and all of the cutting is done y the front edge of the end, when the tool. .is used as a reamer.

WVhen the tool is used as a boring head, the forward longitudinal edge of the cutter is the cutting edge.

Instead of beveling some of the edges in order to obtain the proper clearance for the cutters in starting the cut, I attain the same end by forming. the seat or socket fo the cutter somewhat ahead of the center of the tool, and thereby give the proper clearance on the outer circle in which the ends of the cutters move. This mode of effecting the clearance enables the cutters to be reversed from one cutting edge to another without grinding longitudinal edges, and since the cutter may also be reversed from end to end,

six cutting edges may be utilized, without the necessity of any grinding of the tool.

On the outer surface of the head between the projecting shoulder 7 and the stem 4, is loosely mounted a cutter-adjusting camring 12, provided with cam-projections 13. These projections are adapted to bear against the inner ends of the cutters, and to force the cutters radially outward or to permit them to be retracted, by rotating the cam-ring, in order to regulate the depth of cut.

To provide for the rotation of the camring, the latter has a series of rack teeth 14 cut on a portion of its lower surface, and adapted to be engaged by a special adjusting tool 15 having pinion teeth 16 on one end. This tool is adapted to be inserted in a hole 17, in the head 5, and the pinion portion pushed into engagement with the rack portion of the ring. The tool is provided at its other end with a handle 18, whereby it may be turned so as to move the cam-ring.

A threaded clamping ring 19, engages an outer threaded portion of the-stem and is provided with slanting recesses 21, terminating in shoulders 22. These recesses are adapted to fit over the upper surfaces of the cutters which have edges projected angularly above the plane face of the shoulder, owing to the tilted arrangement of the socket walls, and the shoulders 22 of the clamping ring are adapted to engage and grip theseprojected edges when the ringis screwed into place.

Extending through the clamping ring is a small screw 3, bearing on the cam-ring 12 and serving to hold said ring against its seat so that the proper en agement of the rack with the pinion tool Wi 1 be insured.

In order to lock the cutters in place, the

shoulders thereof engaging the tilted edges of the cutters and then the lock-nut -.t,

is screwed up against the movable head 5, v

out on the tool stem and jammed against the cutters and clampmg ring, thus securely 1 clamping the cutters in place.

To adjust the cutters radially the lock-nut- By the i and with the major width of said cutterexi tending beyond said radius in the direction of the cutting movement so that a clearance of the outer end face behind the cutting edge is effected, whereby the cutter may be adjust-ed so that any one of the edges may be used as the cutting edge, substantially as is loosened and the adjusting pinion-tool 1S,

inserted inthe hole in the head and the camring turned so as to cause a greater or less 5 projection of the cutters, as desired.

It is clear that various changes in the details of thedevice may be made Without departing from the principle of my invention.

Having thus described my invention, what I claim is:

1. In a cutting tool, in combination with a described.

4. In a cutting tool, in combination with a fixed shank stem, a longitudinally slidable head mounted .on said stem, radially movable cutters mounted in said head, pressure means to engage said head and cutters, a ring loosely mounted on said stem and capable of a free longitudinal and rotary movement thereon, said ring having exterior cam-projections adapted to bear against the cutters, and

= having a series of teeth in its inner face, said longitudinally movable head having sockets g in its outer edge, removable cutters mounted in said sockets, a threaded clamping ring beyondsaid head and adapted to bear directly upon said cutters, and pressurei means to hold said cutters locked between said head and ring, substantially as described.

2. In a cutting tool, in combination with a. longitudinally movable head. said head having cutter sockets in its outer edge, remov -able cutters mounted in said sockets and having portions projecting beyond the head, a threaded clamping ring adapted to bear on said projected portions of the cutters and a threaded lock-nut mounted in the tool and adapted to press against the inner end of said head to force the cutters against the ring, substantially as described.

3. In a boring tool, incombination with a. cutter having triangular similar end faces and similar longitudinal faces and having the end faces at right angles to the longitudinal faces, a supporting head, said head having sockets supporting the cutters with said end faces perpendicular to a radius of the tool head having a radial aperture which covers the line of said teeth and is adapted to receive a rotatable toothed tool to operate said toothed ring, substantially as described.

5. In acutting tool, in combination with a tixed shank-stem, a longitudinally movable head thereon, said head having an outer shoulder having cutter-sockets, radially movable cutters mounted in said sockets, a camring loosely mounted in said head behind said shoulder and having a series of teeth on its inner surface, said stem having its outer and inner portions threaded to receive a threaded cutter-clamping ring, and a locknut respectively, means extending through said clamping-ring to press said cam-ring to its seat, said head having a radial aperture extending across the line of the cam teeth to receive a rotatable toothed tool adapted to rotate the cam ring, substantially. as described.

In testimony whereof I .aflix my signature in presence of two witnesses.

, R011 N. BELVIN. Witnesses:

W. H. SACKMAN, HENRY BENDER. 

